The present invention relates generally to an automated warehousing system for storing and retrieving goods, as well as preparing the goods for their ultimate disposition. More particularly, the invention relates to an automated system having a continuous series of mechanisms that are integrated to efficiently manage warehousing material handling operations.
Many modern warehouses require the storage and retrieval of thousands of inventoried items. Often the goods must be stored in bins or containers due to their size or delicate construction. Therefore, storage requires loading the containers and delivering the containers to a known location where they can later be retrieved as necessary. When an order is received, the desired items must be retrieved from their respective storage positions and prepared for either shipping or use. An efficient warehousing operation requires the ability to both store and retrieve a wide variety of goods and to rapidly and effectively dispose of the retrieved items. Heretofore, there have been a wide variety of automated warehousing systems that have been proposed to reduce the labor required in warehousing operations.
Conventional storage and retrieval systems utilize large multi-level fixed storage shelves in combination with an extractor or picking mechanism that must travel to a particular shelf to pick the desired inventory item. Such a system is limited to a small number of transactions each time the extractor is operated. The picked goods are then delivered to a work station where packing, delivery and/or use takes place. More recently, storage structures have been proposed that include a moveable multi-leveled storage carousel having a multiple number of stacks of vertically spaced trays arranged to travel about a frame as shown, for example, in U.S. Pat. Nos. 4,561,820, 4,422,554 and 3,780,852.
Many material handling systems incorporate components aimed at improving the efficiency of the operation. For example, U.S. Pat. No. 3,803,556 discloses a conveyor control system for routing tote pans past various divert stations along a conveyor loop. U.S. Pat. No. 3,792,785 discloses an automated freight terminal for sorting, staging and subsequently loading outgoing shipments in a desired sequence.
Integrated warehousing systems have also been contemplated. For example, Japanese Application No. 53-37829 discloses a method for assorting goods that are stored on storage shelves. The system contemplates removing boxes containing ordered goods from a storage shelf onto a loop-type conveyor which transfers the boxes to a branch line wherein they are reviewed by an operator. The operator looks at the goods in the box and then identifies a customer who needs such goods. He then drives a loop type conveyor to bring a container before him into which the ordered goods may be placed. However, such a system has significant delay times since it is not fully automated and the equipment provided is not organized to maximize efficiency. Although the systems heretofore available have greatly increased the speed and effectiveness of material handling, they still lack the ability to coordinate warehousing activities fast enough to meet current demand in numerous applications.
A typical example may be an electronic product manufacturing and/or repair facility wherein the products built incorporate printed circuit boards. Such warehousing applications may require storage of as many as 150,000 components the vast majority of which would fit into 6".times.6".times.18" compartments. In any given day as many as 1500 assorted components may be drawn from the storage facility. In the environment of a repair facility, there must also be an effective mechanism for storing items that can not be repaired using parts in stock while the unavailable parts are on order. Absent effective integration of the storage system and the repair or manufacturing facilities, the combined man hours lost between delivering the goods to the appropriate work station and the downtime at various work stations as they wait for supplies would become prohibitive.
Another typical example is a consumer products and pharmaceutical warehousing system where on the order of 25,000 stock items must be stored in both case lots and piece lots. The individual stock items may range in size anywhere between 1".times.1".times.1" to 36".times.36".times.18". A representative warehouse may have on the order of 800 customers with in the range of 400 to 800 customers placing orders on any given day. The orders may call for as many as 60,000 individual stock units and the actual number of items requested for each particular stock unit may widely vary. Additionally, rather than sending each customer a truckload randomly containing the ordered goods, it is desirable to package the ordered goods for each customer in smaller lots of related goods. For example, in the consumer products and pharmaceutical application described, related families of products might include RX, hair care products, etc. This allows rapid restocking when the totes are delivered to the retail store.
In any warehousing system, it is desirable to keep very good records of the inventory and the pending orders so that an appropriate amount of inventory may be kept on hand. In this connection there is a need to have a constant record kept of the location of containers loaded onto the storage rack. Similarly, records must be kept as to the actual material goods stored within each container so that the goods can be accessed when needed.
One of the most time consuming and expensive aspects of typical warehousing operations is the need to replenish stocks. Depending upon the nature of the warehousing system in use, replenishment is typically accommodated by either delivering additional stock to the fixed storage location or bringing a container holding the goods to be replenished to a receiving station wherein additional items are added. Such operations are typically very labor intensive.